In recent years, compactness, high output, and high quality have been required in rotary electric machines such as electric motors or generators. With regard to downsizing rotary electric machines of this kind, armature windings that have concentrated windings in which conductor wires are wound onto individual armature core teeth have been used with a view to downsizing coil ends, which do not generate effective magnetic flux. However, armatures that use armature windings of distributed winding construction that can suppress torque pulsation and increase output are in demand. In addition, demand for induction machines that do not use magnets has also increased due to steep rises in magnet prices, and there is demand for armatures that use higher-efficiency distributed winding armature windings.
Here, in contrast to concentrated windings, which are configured by winding conductor wires onto individual teeth, windings that are configured by winding conductor wires into slots that are separated by greater than or equal to two slots are designated “distributed windings”. In other words, distributed windings are wound such that a conductor wire that extends outward from one slot spans two or more consecutive teeth and enters another slot.
In conventional rotary electric machines such as that described in Patent Literature 1, hexagonal winding coils that are formed into a coil shape by winding a rectangular conductor wire a plurality of times are housed in respective pairs of slots that are positioned on two sides of six circumferentially consecutive teeth, to constitute a distributed winding armature winding. Crank shapes are formed without twisting at approximately vertex portions at two ends of the winding coils to suppress axial enlargement of the rotary electric machine, and achieve downsizing.